Ok so first I just had the diff welded - done by the previous owner so I thought I'd give it a go. I put fairly grippy tyres on straight away which granted are not as comfortable as ditch finders - they skip a bit too aggressively but even so, you quickly get used to it. Anything over say 1mph is just like normal. I parallel park every day, go to tesco, work, everything. It's not terrible, even a bit amusing.
On to aggressive driving - I've found this is more to do with tyre choice. I'm not kidding that if I take a roundabout really fast in the wet, it doesn't step out. I'd even go as far as to say it's far far more planted than my 340 ever was. I can't even kick it out on the same corners that I used to (note that this was before it was lowered). Granted that if I was using my 175 drift tyres then sure, it would probably spin. I'd be very happy to hoon down some lanes in a rally even in the wet. It feels very safe.
There's a video floating around of a sierra with a solid rear diff racing - I'm inclinded to believe this is fine now. Most of all guys, it's 100% predictable 100% of the time. You know exactly when the bite is going to start giving and when you should prepare for the fishtail.
I had a bit of fun with it but with the standard suspension I knew it had to change (leaning over waaaay too much in the slides). So I got some lowered springs on the front and adjustable dampers all round. And here's my recommendation to everything - ESPECIALLY drifters. Get adjustable dampers. I'm serious, they are worth more than what you'll pay. They can be as hard as landy dampers (even harder) when you want and then you can cruise home in a lowered car with extreme comfort. That's not an exaggeration.
The only negative I can take away from all this is SCRAAAAAPE. I've had to spend quite a bit of time getting the exhaust raised and it's still not right. Fairly certain I'm going to tear it off on some loose change on the road at some point. Speed bumps have become my enemy and driving around Bristol's potholes and cobbles has become "interesting". But, it's a fair sacrifice.
So there you go, lowered cars and welded diffs. I love it already
The video your on about is dick johnson in his 500bhp sierra destroying bathurst haha 
